This study presents the implementation and validation of a new sediment-scour model with a strict vertex-based, terrain conformal, moving-mesh technique within the framework of OpenFOAM. OpenFOAM lacks the ability to simulate large-amplitude motion needed for analysis of sediment-scour problems, and, thus, its application normally is restricted to small-amplitude cases to prevent computational divergence due to mesh deterioration. The proposed simple, moving-mesh technique in OpenFOAM is implemented to overcome the shortcomings of the conventional automatic mesh-motion techniques in handling large-amplitude moving geometries. The model is used to simulate a simple case of prescribed boundary motion, a previous experiment in the literature, and a new laboratory experiment for local scour due to submerged wall jets. The results are compared with both the experimental and other numerical results. The comparisons demonstrate that the proposed model has the novel advantage of allowing for more severe topographic variations, and can provide more reliable predictions for the key characteristics and evolution of the bed profiles in wall jet scour problems. Furthermore, to improve the practice of modeling wall jet scour, various turbulence modeling approaches and bedload equations also are evaluated and compared.

这项研究提出了一种新的沉积物-冲刷模型的实施和验证，该模型采用了基于OpenFOAM的严格基于顶点的，地形共形的，移动网格技术。OpenFOAM缺乏模拟分析沉积物冲刷问题所需的大振幅运动的能力，因此，它的应用通常仅限于小振幅情况，以防止由于网格退化而导致计算差异。实现了OpenFOAM中提出的简单的移动网格技术，以克服传统的自动网格运动技术在处理大幅度移动几何图形时的缺点。该模型用于模拟规定边界运动的简单情况，文献中的先前实验以及因淹没壁流而引起的局部冲刷的新实验室实验。将结果与实验结果和其他数值结果进行比较。比较结果表明，提出的模型具有允许更严重的地形变化的新颖优势，并且可以为壁喷冲刷问题中的床层剖面的关键特征和演变提供更可靠的预测。此外，为了改善对壁面射流冲刷建模的实践，还对各种湍流建模方法和床载方程进行了评估和比较。